You can search many resources, especially library databases, more successfully by typing in keywords rather than phrases or sentences.Why? Because computers do not think! But computers are good at matching your words with words in the records in the database.
High blood pressure AND coffee AND food
gives different results than
Hypertension AND caffeine AND diet
Citations and abstracts of scholarly, peer-reviewed articles and professional association news and information for thousands of publications. Most comprehensive nursing and allied health database. CINAHL covers nursing, biomedicine, alternative/complementary medicine, consumer health and 17 allied health disciplines.